Improvement in lifting-jacks



HQA. CURTIS.

LIFTING-J'ACK. v No.181,.251, I Patente-d Aug. 22, 1876.

ww @M ffww N.PETERS, PHDTO-LITHDGHAFHER. WAS HINGTON, D. G.

'UNITED S'rAfrEs.

Parini-1vTY OFFICE;

HIRAM A. cunrrs, or -rnnnfrowrt NEwfYonk. 1

IMPRovEMENT'INLiFTiNG-JA-CKSQ Specification forming part of Letters Patent No. 181,215.1, dated August 22, 1876; application filed July 6, 1876.

.To all whom it may concern Be it known thatI, HIRAM ALLEN CURTIS, of the town of Freetown, Cortland county, and State of New York, have invented a new and useful Improvement in Lifting-Jacks, which improvement is fully set forth' in the following specification, reference being had to the accompanying drawings, in which correspondingletters on different figures indicate similar parts, and which drawings are hereby made a part of this speciication.

The objectv of any invention is to furnish an apparatus or machine to lift or raise weights, consisting of logs, stones, bars of iron,and cannons, 8vo., easily and readily.

In the accompanying drawings, Figure 1 represents and shows a side elevation 'of my said apparatus, in which B shows an upright beam or'post of suitable strength to withstand the strain to which it will be subjected. I also make another post or beam, a portion of it being shown at B', Fig. 3. These two posts are placed side by side in an upright position, with a space between them suitable for the insertion of the lever A, which will be more fully explained hereafter. They are then fastened together at the bottom. On the inner side of each of these posts is fastened a plate of iron or other suitable material, and wide enough to project past each side of said posts or beams, as is shown in the drawing. In the four parts thus projecting are formed serrated teeth extending the whole length of the said plates, as shown at H and H', Figs. l and 3, with the notches shown at S and S', which are for the support of the lever A, thus furnishing fulcra, as will hereafter appear. At the top of and between these posts is placed a projecting bar, G. J ointed at a, at the farther end of c, is placed an upright bar, I), working in a recess or mortise in C on the pin b. This bar D has holes in the top at c and d, for the purpose of adjusting the apparatus to uneven ground, which will be seen more fully hereafter. t shows a hook, on which the chain E is fastened. e and e' show rectangular holes, for the purpose of fastening said chain E or its equivalent, the chain E being for the purpose of binding and retaining the weight while it is being raised by the lever A, an end of this chain being fastened to a link',

(shown at J, Fig. 3, which figure shows and represents a portion ofthe inside of the post B and lever A.) Fig. 2 shows the under side of the said-lever A, which is.constructed as follows :v It is made-of suitable length to, supply therequisite power, and of such dimenon said rod. The upper side of each of thesepieces is made flat, so as to rest against thewood-work, as shown in Fig. 3, thus preventing said pieces from turning around on said rod F. The distance between these pieces is regulated by the width of the posts B and B.

On each of the sides of these pieces are beari ings, two'being shown at N and a'. These bearings project over the wood-work of the lever, their size being made to fit into the notches S and S'. Between the clasps N and B and said two pieces are placed two spiral springs, L and L', the rod F passing through them. These springs continually exert their pressure against the pieces K and K', keeping 7 said pieces against the pins passing through the rod F, and shown at r and r'. By4 means of the handle P on the rod F the pieces K and K' can be moved-and made to accommodate the notches S and S'.

Having thus described the construction of my apparatus, I will now describe the. manner of operating the same.

The weight to be raised is secured by the chain'E, the joints in the frame-work (shown at a and b) permitting the apparatus to adjust itself to the position in which it'is placed, the lever A being between the two posts B and B', as shown in Fig. l. By alternately raising and lowering the longer arm of the lever A the bearingsof the pieces K and K' suc cessively adjust themselves in the notches projecting from the inside 'of said posts, as described; aud thus the leverrA, by the continual change of the fulcra, ascends or climbs,

by successive steps, the said notches, and,

consequently, the weight E has to rise, and thus the fulcrum is changed at each move of the said lever-arm, so that alternately a lever ot'lthe` kind known as the `first and second postsB and B. serrated teeth Handi IIQwithj` classesis prod`ueed,`thus securing the advanthenotehesS andl S'tbere`n,"and oth'erfsimilar w I tages of both of these classes of levers. A teeth forming the racks,as described, lever A, t

weight can also be lowered by means -of this chainE', and frame-work C and D, all made` lever. By alternately pulling and pushing on and operated substantially in the manner and the rod F `the bearings on 'theleverA adjust t'or thepurpose ashereindbscribed and shown." themselves into 1ower notches, and thus the lever, with the weight attached,"gradually` de- HIRAM ALLEN "`CURTIS.` scende. e Witnesses:

I 4therefore claim as my inventione JOHN W. SUGGETT,

The combination `and arrangement of the t WM. D. TUTTLE. 

